Electrical controlling system



A ril 20. 1926.

E. F. wATs'oN Er AL ELECTRICAL CONTROLLING S ISTEM Filed March 29, 19242 Sheets-Sheet l INVENTORS EFWm/fl JEM A TTORNE Y April 2o ,1926.1,581,305

E. F, WATSON ET AL ELECTRICAL CONTROLLING SYSTEM I Filed March 29, 19242 She'ts-Sheet 2 9 5/ 013ml; flak-16. Face/2 INVIENQTORS I ATTORNEYPatented Apr. 20, 1926.

UHTED' STATES PATENT OFFICE.

EDWARD F. WATSON, OF LARCHMGNT, AND ARTHUR E. HUNT, OF NEW YORK, N. Y.,

ASSIGNORS T0 AMERICAN TELEZEONE AND TELEGRAPH COMPANY, A CORPORA- TION62 NEW YORK.

ELECTERICAL CONTROLLING SYSTEM.

Application filed March 29, 1924. Serial No. 702,902.

To (Z Z whom it may concern Be it known that we, EDWARD F. VVATsON andARTHUR E. HUNT, residing at Larchmont and New York, in the counties ofNest-chester and New York and State of New York and New. York,respectively, have invented certain Improvements in ElectricalControlling Systems, of which the following is a specification.

This invention relates to electrical controlling systems, andparticularly to means for correcting the distortion ofsignaiing impulsesSuch as are used in printing telegraph systems.

In order to obtain eiiicient operation printing telegraph systems, it isnecessary to elim nate the efl'ect of distortion upon the receivingapparatus connected with the line circut over which the signalingimpulses are transmitted and which is the princpal source of suchdistortion. If a signal is torted in the course oftransmission over aline. an impulse of wrong polarity may be applied to a segment of thereceiving distributor of the printer, which in turn produces anincorrect signal character in the apparatus associated therewith. Adevice for determining the existence oi distort on of tele raph signalswithout discontinuing the transmision of commercial service over thecircuit is disclosed in the co-pending application of TVatson, SerialNo. 638,121-, filed May 10, 1923. The invention therein disclosed simplyindcates the presence of distortion and it is necessary to make a.manual. adjustment of the apparatus in order to correct for the saiddistortion.

It is the object of this invention to pro-- vide a method and means forautomatcally com ensating for the distortion or bias in signals receivedby a telegraph repeater or terminal circuit connected with a line. A.further object of the invention is to provide means whereby a pluralityof such repeaters or terminal circuits may be successively tested fordistortion and automatically adjusted to compensate for such distortion.A. further object consists in the provision of means for signaling arepeater attendant in case the distortion becomes of such magnitude thatthe compensating apparatus cannot make sufiicient adjustments to compen-S e f r Such disto ti Other objects of this invention will be apparentfrom the following description, when read in connection withthe'attached drawing, of which Figure 1 shows, in general, the aplication of the invention to a plurality 0 f duplex telegraph circuits;Fig. 2 shows in detail the driving mechanism for moving the rheostatswhich eiiect the adjustment of the circuit to compensate for the minalcircuit at B being substantially iden-' tical to that at A with theexception that the cr-u'ipensatmg apparatus shown at A is omitted at Bfor simplicity. The terminal circuit at A comprises the bridge coils 2and 3, the junction point of which is connected with the armature of thepole changer 4. This armature, which is controlled by the operation ofthe transmitting apparatus connccted with the loop circuit, applies impulses of opposite polarity from the batteries 5 and 6 to the line. Thearmature of the receiving relay 7 is adapted to apply impulses ofcurrent from the battery 8 to that branch of the receiving circuitincluding the sounder 9 and the control relay 10. By the operation ofthe control relay, the loop circuit is opened and closed at the contact11, thereby transmitting open and closed impulses to the subscribersstation, herein represented as comprising printing telegraph apparatus.The contact 12 of the control relay 10, which opens whenever contact 11opens and, vice versa, closes whenever contact 11 closes, controls theaction ofthe holdirg winding, that is, the upper winding, as shown inthefigure, of the pole changer 4. The branch of the receiving circuit whichincludes the sounder 9 and the control relay 10 wili hereinafter bereferred to as the control relav circuit. This circuit includes therheostat 13 and the circuit is normally closed through the contact 14which is closely located to the distributor face No. 1. This contact is$0 arranged that it will be opened by the rotating arm of distributorface No. 1 during the interval in which the line 1 is einp; tested fordistortion. The distributor line No. 1 comprises four rings, two ofwhich, designated and 16, are segmental, and 17 and 18 are continuous.lhe rotat inc arm 19 of this distributor carries two brushes 20 and 21,both of which are iii-- sulated from the arm. Brush 20 is adapted toconn ct [l c segments o1 ring 15 with the udjacen r manner, rush 1 1 tinc; 17, and in like 31 makes a connection between the segments of ring;16 and ring 18. The extension oi? arm 19, which designated 22, isadaptcd to open the normally closed contact 1 1 of the control relaycircuit during the interval in which the brushes 20 and E21 upon thesegments 93 and 2-1 connected with the line circuit 1. to be tested. Thedistributor face No. 1 is intended to successively connect with theeon'ipensating control circuit ten lines such as 1., each having its ownteri iinal circuits connected therewith. For the sake of simplicity,only one complete circuit, viz, line 1 and the terminal circuit atstation A will be shown connected with this d str bu tor but it is to beunderstood that the leads taken out from the other segments of rings 15and 16 are to be connected with control relay circuits ot the ter nalcircuits of other he The continuous rings 17 and 18 are connected byconductors 9 and T0 with the line relay 26 associated with thedistributor "face No. 2 This distributor face is. in general, similar tothat used in the startstop tvpe f printers coinnrisinp; two

0 mental riigs tl e outer ring ba ing a pluspaced. ccgment S is normallyconnected with the nrr tineapparatus and segment 8,

tarting; oi: the distributor. terposet i are scgnnents and S segment Sbeing connected over conduct-or 28 and through contact with the battery30. Segment F5, is

turn is connected by conductor through contact with the battery 30.Relays H E J? rahty 0; segments of equal size and equally i u controlsthe s Inbetwecn segments t and Q nected with relay H, which in turn isconsiin' connected with relay L, which in and. 1 control the magnets and36 respectively. The fifth segment is connectcd with the winding; 0?relay 31, the function of which is to open the cirzuit of 1'Blt1 ;'S

l-l l .1. in the event that the fifth impulse received bv tl e apparatusover the line 1 is closed impulse. The reson for doing so will be iradeclear later,

The inner ring comprises two seeginents. desigi ated tri and 5 C ne ofthe divisions between these segments coincides in radial position withthe division between segments bi, ai'id S ()ne of the contacts of relayconnected with segine it S and the other with The arm of thisdistributor can rise the brush. 33' n's'u'lated therefrom, which isadagted to connect the segments of the inner and outer rings of thisdistributor. This arm is controlled in its operation by the startingmagnet 34.

The mechanism for etfecting the rotation of the arms of distributorfaces No. 1 and K0. 2 and also for controlling the rheostat 13 is shownclearly in Fig. 2. In this figure, is the revolving brush arm ofdistributor face No. 2. whicn is driven by a motor through the shaft 40,worm a1, worn gear 4-2, shaft 4-3 and friction clutch 4st. Attached to ain 32 is the brush 33 as shown in connection with the distriluitor faceNo. 2111 l? 1. This brush makes contact with the segments of thedistributor face lilo. 2. On the shaft 46 connected with the worm -ft1is a governor to con rol. the speed of rotation of the brush ar n 3; andto keep it unilorm. This arrangement is similar to that in use inconnection with the well-known startstop type of distributors, with theex eption of the size of the segments of the distributor face lh. 2.Connected with the shaft 4-3 is a spur gee 1 t? which meshes with thegear 48 connected with the shatt- 49. This shaft also carries the spurgear 50 which meshes with the gear 51 connected with the shaft 52. Theshaft also carries a onetooth rear "3 which coacts with the internalgear connected with the shaft to which is attached the brush ain 19 hedistributor face No. 1. The l7, 41S. 50 and 51 give aspeed reduction ofto 1, so that the single tooth gear makes one revolution for 25revolutions of shaft 43. The internal gear 5-1 has ten teeth, so thateach revolution of gear 53 advances gear 5 1 the distance of one toothor one-tenth of: a revolution. lhis means that shaft and brush arm 19rotate one-tenth of a revolution for every 2? revolutions of shaft 53.Attached to the brush arn 19, as mentioned heretofore, are the brushes20 and 21 which make contact with the segments ot the distributor faceNo. 1. at the end of the shaft are two bevel gears 56 ando'hthelatterot'which is onnected with the shaft 58 which serves to operate the rheostatcontrol ing inechanism.

The shaft 58 'ries a plurality 01 cams, one for each rheostat. Such acam is shown clearly by 59 of Fig. 3 This am causes the. idler gear 60to eng e of the rheostat, will be operated by g ar 62 whenever theratchet wheel Gel is open ated b the magnets and S6 sh: in l ke 1 and inn rater detail in F i. Tue

idler cjear G0 is uorn I the gears 51 and 6&2. so that gear (51, towhich is attached the arm 35 or is energized, and the direction ofrotation depends, of course, upon which magnet is energized. As will beseen in Fig. 2, this ratchet wheel is connected with the shaft 66 townich is also attached the gear it w'll accordin ly be seen thatwhenever the projection or the cam 59 de presses the gear 60 intoengagement with th gears 61 and 62, the arm of the rhcostat will bemoved in direction or the other henever the magnet, and 36 are ener- L.ed. As will later be seen, this movement of the arm of the rheostatvaries the re sistance 13 in the control relay circuit and effects suchadjustment that the bias of the is compensated for. The arrange ment inFig. 2 shows a plurality of rheostats connected with the shafts 58 and66 by means of which the bias in a plurality of terminal circuits may becompensated for.

Having in mind the foregoing description of the apparatus and of thecircuit in which this invention is embodied, the invention itself willbe made clear by the following de scription of the mode of operating thecircuit.

In the well-known start-stop printing telegraph system, for eachcharacter there will be transmitted an open or start impulse followed byfive selecting impulses, each of which may be either open or closed, andthen a closed or stop impulse. By the term open impulse is meant animpulse of such character as to deenergize the line relay 26 and thecontrol relay 10 and to allow their armatures to drop back, andsimilarly, the term closed impulse means one that will energize theserelays so that their armatures will be attract- The existence andmagnitude of distortion is determined by investigating the condition ofthe sixth impulse, which, if understood, is applied to the line relay 26while the brush 33 is moving from segment S to 3,. Any distortion ofthis impulse, namely any lengthening or shortening thereof, will causethe operation of either relay H or L and will, in turn, effect theoperation of the compensating rheostat. In the start-stop printingtelegraph system, the sixth impulse is always a closed impulse for eachsignal character transn'iitted. The biased condition of this sixthimpulse/controls the operation of the compensating device for eachcharacter except those in which the fifth impulse'is closed. Where thiscondition prevails, the bias compensating de vice is renderedinoperative in order to prevent improver operation due to the fifthimpulse overlapping on to segment S Since the fifth impulse is a closedone 1n only a few signal characters, it will be: apparent fromsubsequent description of the operation of this device that this doesnot ali'ect to any important degree the usefulness of this device,mentiopedhefore,

lay 10, contacts 11 and 12 are closed.

segments S andS are ofequal size and are located between segment 5,,designed to receive the fifth signal impulse, and segment S designed toreceive the sixth or printing the line relay 26 would be operated at thein st-ant the brush 33 1s passing over the division between segments Sand 5,. Since this imimpulse. When the signals are undistorted, J

pulse is a closed impulse, relay 26 will be energized and the left-handcontact, namely that which is connected with the segment Let us assumethat the sixth impulse has been transmitted over line 1 and that thereceiving relay 7 has beenenergizcd, so that its armature will move tothe position shown in Fig. 1. Current will then flow from battery 8through the upper contact of relay 7, thence over a circuit includingthe sounder 9, resistance 13, conductors 67 and 68, segment 23, ring 17,conductor 69, line relay 26, conductor 70, ring 18, segment 24:,conductors 71 and 72, and control relay 10. Since this circuit isclosed, relays 26 and 10 will be energized. By the energization of relay26, its armature is attracted to its righthand contact, and by theenergization of re- The closing of contact 11 establishes a circuit fromthe grounded battery 7 3 to the grounded battery 74-, therebytransmitting a 'eloscd impulse to the printing telegraph apparatusconnected with the loop circuit. The control relay circuit is closedthrough the line relay 26 for the reason mentioned heretofore, namelythat the contact 14 is opened after the brushes of arm 19 move on to thesegments 23 and 24, which are assigned to the particular circuit shownin Fig. 1. Furthermore, since the arm 19 is connected with the shaft 55,which is rotated by the single tooth gear 53- one-tenth of a revolutionfor .each' 25 revolutions'of the shaft 4-3, to which the brush arm 32 ofthe distributor face No. 2 is connected, it will be seen that thecontrol relay circuit of the terminal circuit at station A connectedwith line 1 will remain connected with the line relay of the distributorface 2 during the time in which the arm of distributor face No. 2 ismaking 25 revolu tions. This interval of time represents the receipt ofapproximately twenty-two signal characters, each made up of five signalimpulses and a sixth or printing impulse. This duration of time issufiicient to determine cond tion at we ys xth impulses.

7 transmitted over the line 1 and to effect compensation for any bias ordistortion of these impulses produced by line or repeater apparatusconditions. The distributor arm 32 is synchronized with the transmittingdevice at station E and the distributor face No. 2 is initially adjustedto put the apparatus in such condition that with undistorted signals thebrush 33 01? arm 32 should be passing across the division betweensegments S and S when the relay 26 is energized by the sixth or closetimpulse.

Let it be assumec that the tongue of relay 7 touches its upper contactand thereby transmits a closed impulse over the control relay circuitduring the time in which the brush 33 is passing over the segment S thatis to say just 36f016 it reaches the division between S and S Relay .26will accordingly be energized, so that the segment S will be groundedthrough the right-hand contact of this relay. Since at this instant thebrush 33 connects gments S and S a circuit will be established frombattery 3th over contact 29, conductor 28, winding of relay H andthrough s gments S and S to ground. Relay H will be energized and, inconsequence thereofl the magnet 35 associated therewith will also beenergized by current from the battery 30. The attraction of its armaturewill cause the rotation of the wheel 6 1, shown in detail in Fig. 4,which, by virtue of its being connected with the shaft 66, will effectthe rotation of the gear 62. When the arm 21 ot the distributor face No.1 is in the position showin the shaft 58 has beeen rotated to suchposition that the cam 59 has depressed the gear 60 into position whereit meshes with gears 61 and 62, so that when the toothed wheel 64; isrotated by the action of the magnet 35, gear 61 will also be rotated andthe arm 69 will be moved in such direction as to increase the resistancein the control relay circuit that is to say. the resistance 13.

It the signals are biased light, the sixth impulse will not be receiveduntil after the brush 33 has passed on to segment S that is to say, theline relay 26 and the control relay 10, which serves to control theimpulse applied to the loop circuit, will not be energized until thisinstant of time. Conse quently. when the brush 33 passes on to s gment Sthe relay 26 is not operated and the grounded armature is against itslefthend contact. There will. be established a circuit from battery 30,through contact 29 and conductor 28 winding of relay L and segments Sand S to ground. This will cause the operation of relay L, which in turnwill cause the operation of the magnet 36 by current from the samesource 30. The operation of magnet 36 will cause a movement of thetoothed wheel 64- in opposite direction to that in the case mentionedabove.

Accordingly, the gear 62 will be moved in opposite direction, and sincethe gear 60 is meshed with gears 61 and 62, the arm 63 of the rheostatwill be moved in opposite direction to that previously mentionedso todecrease the resistance in the control relay circuit and thereby toincrease the current. This increase oi current will tend to overcome thelightness of the signal and to compensate tor the bias.

It the tltth impulse is a closed impulse, the compensating apparatuswill not eiiiect the desired result. In order to prevent falsecompensation means have been provided for eti'ectively disconnecting thecompensating apparatus in the event that the fifth. impulse is closed.This disconnecting apparatus consists in the relay connected with thesegment S It the fifth impulse is closed when the brush 33 moves overthe segment S the relay 26 will be energized and a circuit will beestablished from bat tery 30 through winding oi relay 31, segments and Sand right-hand contact of relay 26 to ground. This opens the uppercontact 29 of this relay and disconnects the battery 30 from relays Hand L and their associated magnets. Relay 31 is locked up and remains sountil the start impulse tor the next signal character is received. Thisavoids a false adjustment of the relays controlling the compensatingrheostat.

As will be seen in 3-, if the arm 63 is moved sufiiciently far in eitherdirection, it will close the contacts 73 or 7e and will cause theoperation of a signal lamp or other device ter attracting the attentionor the repeater attendant. This indicates that the bias is so great thatthe automatic compensating apparatus will not sufiiciently correct hedithculty and it requires the manual adjustment by the repeaterattendant.

After the shaft 15 ot' the distributor face No. 2 has rotated 25 times,the single toothed gear engages with the internal gear 54: and moves theshaft 55 one-tenth of a revolution. This moves the arm 21 of distributorface No. 1 on to the succeeding segments which are connected withanother terminal circuit or repeater, as shown in 1, The movement ofshaft 55 also moves shaft 58 onetenth of a revolution which operates acam 59 and effectively connects the gears 61 and 62 for controlling therheostat 13 of another terminal circuit or repeater similar to thatshown completely in 1. The distributor face No. 1 is shown with ten setsof segnnmts rendering it p ssib e to test ten tern'iinal circuits orrepeaters such as are shown connected with the lines 1 and 1. It is, ofcourse, to be understood that the number of circuits to be tested may bevaried by increasing or decreasing the number of sets of segments uponthe distributor face No. 1. As soon as the arm 21 has been rotated sothat the brushes and 21 pass on to the next scements 23 and 24.-connected with the circuit shown in Fig. 1, the control relay circuit ofstation A is closed through by the closing or contact 1%. The contact isso positioned in regard to the cam that the brushes must he on thesegments such vas 23 and 2% store the contact 14 is opened, and also thecontact must be closed before the brushes pass on to the next succeedingsegments. This prevents the possibility of opening the control relaycircuit and interrupt-ing the receipt of signals from the sendingstation.

While this invention has been disclosed as embodied in a particularform, it is to be understood that it is capable of embodiment in otherand diiierent forms without departing from the spirit and scope of theappended claims.

What is claimed is:

1. In a system for compensating for bias of telegraph signals consistingof a lengthening or shortening of an impulse, the combination with aline of terminal circuits having printing telegraph apparatus connectedtherewith and means to automatically adjust the said terminal circuitsto compensate for bias of the signals.

2. In a system for compensating for bias of telegraph signals consistingof a lengthening or shortening of an impulse, the combination with aline of terminal circuits having printing telegraph apparatus connectedtherewith, and means responsive to and controlled by the printingimpulse transmitted with each signal character over the said line toautomatically adjust a terminal circult to compensate for bias of thesaid printing impulse.

8. In a system for compensating for bias of telegraph signals consistingof a lengthening or shortening of an impulse, the combination with aline of a terminal circuit having means responsive to signal impulsestransmitted by the said line and applied to the said terminal circuit,and means connected with the terminal circuit and controlled by impulsesreceived from the said line to compensate for bias of the signals.

d. In a system for compensating for bias of telegraph signals consistingof a lengthening or shortening of an impulse, the comination with a linehaving terminal circuits connected therewith adapted to apply signalsconsisting of impulses of opposite polarity to the said line, and :meansconnected with one of the said terminal circuits responsive to thesignaling impulses applied by the said line to the said terminal circuitand adapted to control compensating means to correct for the bias of animpulse.

5. In a system for compensating for the bias of telegraph signalsconsisting of a lengthening or shortening of an impulse,

the combination with a duplex telegraph cirpulse.

6. In a system for compensating for bias of telegraph signals consistingof a lengthening or shortening of an impulse, the coinbination with aplurality of lines each having a terminal circuit having apparatus re-'sponsive to signaling impulses sent over the line connected thereto, andmeans connected with each terminal circuit and common to all of saidcircuits to adjust automatically the respective terminal circuits tocompen-' sate for bias of received signals.

7. In a system for compensating for bias of telegraph signals consistingof a lengthening or shortening of an impulse, the combination with aline of a printing telegraph transmitter connected with one end ofthesaid line to apply impulses thereto, a polar relay connected with theopposite end of the said line responsive to the said impulses, areceiving circuit, controlled by the said polar relay, having a. currentvarying de vice connected therewith, and an impulse testing arrangementcomprising means responsive to biased impulses, operatively connectedwith the said current varying device, to actuate the latter inaccordance with the degree and the nature of the bias.

8. In a system for compensating for bias of telegraph signals consistingof alengthening or shortening of an impulse, the combination with a lineof a printing telegraph transmitter connected with one end of the saidline to apply impulses thereto, a polar relay connected with theopposite end of the said line responsive to the said impulses, areceiving circuit, controlled by. the said polar relay, having a currentvarying device connected therewith, a relay connected with the saidreceiving circuit, a plurality of electro-responsive devices con nectedwith the said current varying clevice, and switching means'to connectthe said relay with the said electro-responsive device whereby the saiddevice will be actuated and the said current varying device will beoperated.

9. In a system for compensating for bias of telegraph signals consistingof a lengthening or shortening of an impulse, the com bination with aplurality of lines, of printing telegraph transmitters individual to andconnected with each of the said lines, polar relays individual to andconnected with each of said lines, a receiving circuit for each linecontrolled by its polar relay and having current varying means connectedtherewvitl), an impulse testing device common to all lines comprisingcompensating means responsive to biased impulses operatively connectedWith the current varying device, of each receiving circuit, andswitching means to connect the said compensating means With thereceiving circuit of each line circuit for a limited period of time. 1

In testimony whereof, We have signed our names to this specificationthis 27th day of March, 192%.

EDWARD F. WATSON. ARTHUR E. HUNT.

